System for supplying fluid to transmission control elements

ABSTRACT

A system for supplying fluid to transmission control elements includes a body producing clutch-apply pressures and a lube source, clutches, each clutch including a servo and a balance volume, a shaft including passages, a support including paths communicating each of the clutch-apply pressures and the lube source to a respective passage, and a clutch hub communicating clutch-apply pressure from each of the passages to a respective servo, and communicating the lube source to the balance volumes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an apparatus for supplying fluid toclutch and brake control elements of an automatic transmission and to atransmission lube circuit.

2. Description of the Prior Art

An automatic transmission for a motor vehicle capable of producing alarge number of forward gear ratios may require several brakes and fouror more clutches to control its operation. In addition such atransmission may require two or three passages of oil feed to its torqueconverter.

A need exists in the industry for a technique that feeds automatictransmission fluid (ATF) to the torque converter, clutches, brakes and alube circuit through a front support assembly such that the axial lengthof the transmission is minimized. The ATF must be supplied to a separateoil path for each clutch-apply circuit, the lube circuit and each of thetorque converter circuits while providing sealing between the paths,adequate flow area, and connections from a hydraulic control bodythrough the pump support.

SUMMARY OF THE INVENTION

A system for supplying fluid to transmission control elements includes abody producing clutch-apply pressures and a lube source, clutches, eachclutch including a servo and a balance volume, a shaft includingpassages, a support including paths communicating each of theclutch-apply pressures and the lube source to a respective passage, anda clutch hub communicating clutch-apply pressure from each of thepassages to a respective servo, and communicating the lube source to thebalance volumes.

In conventional automatic transmissions having multiple rotatingclutches and a three-passage torque converter, an extra supportstructure in the center of the trans (called a center support) isrequired to allow passage of one or more of the rotating clutches. Thissystem provides feeds for all the clutches and the lube circuit withoutadding a center support.

The scope of applicability of the preferred embodiment will becomeapparent from the following detailed description, claims and drawings.It should be understood, that the description and specific examples,although indicating preferred embodiments of the invention, are given byway of illustration only. Various changes and modifications to thedescribed embodiments and examples will become apparent to those skilledin the art.

DESCRIPTION OF THE DRAWINGS

The invention will be more readily understood by reference to thefollowing description, taken with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of the kinematic assembly of an automatictransmission for a motor vehicle;

FIG. 2 is a cross sectional side view of an intermediate length portionof the kinematic assembly of FIG. 1 showing a clutch housing;

FIG. 3 is a cross sectional side view of a front length portion of thekinematic assembly of FIG. 1 showing a brake assembly;

FIG. 4 is a cross sectional side view of a length portion of thekinematic assembly of FIG. 1 showing hydraulic passages;

FIG. 5 is a cross sectional end view in the pump support showinghydraulic passages; and

FIG. 6 is a cross sectional side view of a length portion of thekinematic assembly of FIG. 1 showing hydraulic passages that supply therear clutch.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The assembly 10 FIG. 1 includes an input 12; output 14; intermediateshaft 16; a first planetary gear set 20 having a first sun gear 22, afirst ring gear 24, a first carrier 26; and a set of planet pinions 30supported on carrier 26 and in continuous meshing engagement with thesun gear 22 and the ring gear 24.

A second planetary gear set 32 includes a second sun gear 34 fixedlycoupled to sun gear 22; a second ring gear 36; a second carrier 38fixedly coupled to the input 12; and a set of planet pinions 40 insupported on carrier 38 and in continuous meshing engagement with sungear 34 and ring gear 36.

A third planetary gear set 42 includes a third sun gear 44 fixedlycoupled to ring gear 36; a third ring gear 46; a third carrier 48; and aset of planet pinions 50 supported on carrier 48 and in continuousmeshing engagement with sun gear 44 and ring gear 46.

A fourth planetary gear set 52 includes a fourth sun gear 54 fixedlycoupled to ring gear 46; a fourth ring gear 56 fixedly coupled by ashell 58 to carrier 26; a fourth carrier 60 fixedly coupled to output14; and a set of planet gears 62 supported on carrier 60 and incontinuous meshing engagement with sun gear 54 and ring gear 56.

A first brake 64 selectively holds ring gear 24 against rotation.

A second brake 66 selectively holds sun gears 22, 34 against rotation onthe transmission case 124.

A first clutch 68 selectively couples ring gear 36 to a clutch housing70.

A second clutch 72 selectively couples carrier 48 to clutch housing 70.

A third clutch 74 selectively couples ring gear 46 and sun gear 54 toinput 12.

A fourth clutch 76 selectively couples shell 58 to clutch housing 70.

FIG. 2 shows that carrier 26 is secured to shell 58.

Clutch housing 70 includes an axial arm 82 formed with internal spineteeth, to which external teeth on the spacer plates 84 of clutch 68 arefixed for rotation with clutch housing 70. The friction plates of clutch68 are splined to external spline teeth formed on a ring 85, which isformed with ring gear 36.

Intermediate shaft 16, which extends along axis 86 on the radial outerside of input 12, is secured to ring 85 where a snap ring 88 completesthe connection. Clutch housing 70 is supported by axially spacedbushings 90, 92 on the radial outer surface of intermediate shaft 16.

Clutch housing 70 includes another axial arm 94 formed with externalspine teeth, to which internal teeth on the spacer plates 96 of clutch76 are fixed for rotation with clutch housing 70. The friction plates ofclutch 76 are splined to internal spline teeth formed on a shell 58.

External teeth 98 on the spacer plates of clutch 72 engage internalspline teeth formed on arm 94 of the clutch housing 70. The frictionplates of clutch 72 are splined to external spline teeth formed oncarrier 48.

Located between bushings 90, 92 and formed in the hub 100 of clutchhousing 70 are four feed circuits. A single balance oil feed suppliesautomatic transmission fluid (ATF) to the pressure balance volumes 102,104, 106 of clutches 68, 72, 76. Balance dams 103, 105, 107 seal thepressure balance volumes 102, 104, 106 at the pistons 110, 112, 114 ofthe clutches 68, 72, 76.

Each of the servo cylinders 69, 73, 77 of clutches 68, 72, 76 issupplied with actuating pressure through individual circuits formed inthe clutch housing 70. When no actuating pressure is applied to clutches68, 72, 76, the clutch housing 70 has no fixed connection to any othercomponent of assembly 10.

FIG. 3 shows a pump support 120 secured by bolts 122 to the transmissioncase 124 and supporting the input shaft 12 on a bushing 126. A hub 128for brakes 64, 66 includes a radial arm 130, secured to the pumpsupport, and an axial arm formed with external and internal axialsplines, to which the spacer plates of the brake and clutch are secured,respectively.

The friction discs 132 of brake 66 are connected to external, axialspline teeth formed on a disc 134, which is secured to the sun gears 22,34 through intermediate shaft 18. The friction discs 136 of brake 64 areconnected to internal, axial spline teeth formed on a disc 138, which issecured to ring gear 24 and is supported between two thrust bearings 140located on the carrier 26.

The planet pinions 30 of gearset 20 are supported for rotation on apinion shaft 142, which is supported on carrier 26.

Pump support 120 is formed with a first cylinder 144 containing a piston146, which extends though openings 148 into contact with one of thespacer plates of brake 64. Brake-apply pressure is carried throughpassages 150, 151 to cylinder 144. The openings 148 in hub radial arm130 allow an assembler of the brake hub assembly to see though the armwhile aligning friction plates 136 with disc 138.

Pump support 120 is also formed with a second cylinder 154 containing apiston 156, which contacts one of the spacer plates of brake 66.Brake-apply pressure is carried through passage 158 to second cylinder154.

The radial arm 130 of the brake hub 128 is secured to the transmissioncase 124 such that the arm contacts an axial stop 152, which limitsaxial displacement of the arm and provides an axial reaction force tothe force of piston 146 applied to the plates of brake 64 and the forceof piston 156 applied to the plates of brake 66.

FIG. 4 shows a torque converter 198 enclosed by an impeller housing 160,162, which is driveably connected to an engine shaft or other powersource. A drive 164 is driveably connected to impeller housing 160. Anidler gear 166, supported on a bearing 168 and meshing with the drivegear, is driven by impeller housing 160 in rotation about axis 170. Agear 172, meshing with idler gear 166, is connected by a spline to arotor shaft 174, which rotates about axis 176.

The rotor 178 of a variable displacement pump 180, secured to the rotorshaft 174, draws automatic transmission fluid (ATF) into the pump'sinlet from an oil sump 182, through a filter 184 located in the sump.ATF exiting the outlet of pump 180 flows sequentially through passage186, a hydraulic control body 188, a series of oil feed paths 190 and aseries of drilled oil feed holes 192. The oil feed holes 192 are formedin transmission case 124.

The pump support 120 is formed with drilled oil feed paths directedtoward axis 86 in the pump support 120. Each oil feed path connects oneof the drilled oil feed holes 192 with a corresponding oil feed channel194. Drilled holes in a torque converter stator shaft 196 connect eachof the channels 194 to input shaft 12 and to the torque converter 198located within housing 160.

Referring now to FIGS. 4 and 5, one of the oil feed holes 192 isconnected by feed path 200 in pump support 120 to a feed channel 202,through which the torque converter 198 is charged with ATF throughpassage 204.

Another one of the oil feed holes 192 is connected by feed path 206 inpump support 120 to a feed channel 208, through which a torque converterlockup clutch is actuated through passage 210.

One of the oil feed holes 192 is connected by feed path 212 in pumpsupport 120 to a feed channel 214, through which the torque converter198 is released.

FIG. 5 shows the feed path 151 and passage 150, through which brake 64is actuated.

One of the oil feed holes 192 is connected by feed path 216 in pumpsupport 120 to passage 158, through which brake 66 is actuated.

One of the oil feed holes 192 is connected by feed path 218 in pumpsupport 120 to a feed channel 220, connected though an axial passage 222in input shaft 12, through which clutch 68 is actuated.

One of the oil feed holes 192 is connected by feed path 224 in pumpsupport 120 to a feed channel 226, connected though an axial passage ininput shaft 12, through which clutch 72 is actuated.

One of the oil feed holes 192 is connected by feed path 228 in pumpsupport 120 to a feed channel 230, connected though an axial passage ininput shaft 12, through which clutch 74 is actuated.

One of oil feed holes 192 is connected by feed path 232 in pump support120 to a feed channel 234, connected though an axial passage in inputshaft 12, through which a lube circuit is supplied. The lube circuitcarries ATF to the balance volumes of clutches 68, 72, 74, 76 throughaxial passage 262, as shown in FIG. 6.

Each of the four axial passages in input shaft 12, through whichclutches 68, 72, 74 are actuated and the lube circuit is supplied, ismutually parallel and parallel to axis 86.

Three of the axial passages in input shaft 12 communicate through clutchhousing 70 to the servo cylinders of clutches 68, 72, 74 through oilfeed paths in the clutch housing similar to those described withreference to the pump support 120 of FIGS. 4, 5. The axial lube passagein input shaft 12 also communicates through clutch housing 70 to thebalance volumes 102, 104,106 of clutches 68, 72, 74 through oil feedpaths in the clutch housing 70 similar to those described with referenceto the pump support 120.

FIG. 2 shows the axial 240 and radial 242 passages, through whichclutch-apply pressure is supplied to clutch 72, and the axial 244 andradial 246 passages, through which lube is supplied to the balancevolumes 102, 104, 106 of clutches 68, 72, 76, respectively.

FIG. 6 is a cross sectional side view of a rearward portion of thekinematic assembly of FIG. 1 showing hydraulic passages that supply lubeand clutch-apply pressure to clutch 74. A passage 248 carries fluid fromthe control body 188, through the oil sump 182 and transmission case124, to a radial passage 250 formed in the output shaft 14. Aligned andconnected axial passages 252, 254 in output shaft 14 and input shaft 12,respectively, hydraulically connect passage 250 and radial passage 256,which carries clutch-apply pressure to the cylinder 258 of the servothat actuates clutch 74.

The same lube passage 262 in input shaft 12 that carries lube toclutches 68, 72, 76 also carries ATF lube to clutch 74 from source oflube in control body 188. Axial passage 262 in input shaft 12 ishydraulically connected to a radial passage 264, which carries lube tothe balance volume 266 of clutch 74.

In accordance with the provisions of the patent statutes, the preferredembodiment has been described. However, it should be noted that thealternate embodiments can be practiced otherwise than as specificallyillustrated and described.

The invention claimed is:
 1. A system for supplying fluid totransmission control elements, comprising: a body producing clutch-applypressures and a lube source; clutches, each clutch including a servo anda balance volume; a shaft including passages; a support including pathscommunicating each of the clutch-apply pressures and the lube source toa respective passage; a clutch hub communicating clutch-apply pressurefrom each of the passages to a respective servo, and communicating thelube source to the balance volumes; a torque converter including alock-up clutch passage; and wherein the body produces lock-up clutchpressure, and the support paths include a path that communicates lock-upclutch pressure to the lock-up clutch passage.
 2. The system of claim 1,wherein: the body produces a clutch-apply pressure for each of three ofthe clutches; the shaft passages include four passages, each of first,second and third of the passages communicating clutch-apply pressure toone of the clutch servos, and a fourth passage communicating the lubesource to the balance volumes.
 3. The system of claim 1, furthercomprising: brakes, each brake including a brake servo; and wherein thebody produces brake-apply pressures, and the support includes secondpaths that communicate each of the brake-apply pressures to a respectivebrake servo.
 4. The system of claim 1, further comprising: a brakeincluding a brake servo; and wherein the body produces brake-applypressure, and the support includes a path that communicates thebrake-apply pressure to the brake servo.
 5. The system of claim 1,further comprising: the torque converter including a converter chargepassage; and wherein the body produces converter charge pressure, andthe support paths include another path that communicates convertercharge pressure to the converter charge passage.
 6. The system of claim1, further comprising: the torque converter including a converterrelease passage; and wherein the body produces converter releasepressure, and the support paths include another path that communicatesconverter release pressure to the converter release passage.
 7. A systemfor supplying fluid to transmission control elements, comprising: a bodyincluding a lube source and producing clutch-apply pressures for each ofthree clutches, each clutch including a respective servo and a balancevolume; an input shaft including four passages, each of first, secondand third of the passages communicating clutch-apply pressure to one ofthe clutch servos, and a fourth passage communicating the lube source tothe balance volumes of the clutches; a fourth clutch including a fourthservo and a fourth balance volume; an output shaft including a fourthclutch-apply passage, the output shaft including a fifth passage thatcommunicates the fourth clutch-apply passage to the fourth servo, thefourth passage communicating the lube source to the fourth balancevolume; a hydraulic path communicating clutch-apply pressure from thebody to the fourth clutch-apply passage.
 8. The system of claim 7,further comprising: brakes, each brake including a brake servo; the bodyproduces brake-apply pressures; and a support that includes paths thatcommunicate each of the brake-apply pressures to a respective brakeservo.
 9. The system of claim 7, further comprising: a brake including abrake servo; the body produces brake-apply pressure; and a supportincludes a path that communicates the brake-apply pressure to the brakeservo.
 10. The system of claim 7, further comprising: a torque converterincluding a converter charge passage; and the body produces convertercharge pressure; and a support that includes a path that communicatesconverter charge pressure to the converter charge passage.
 11. Thesystem of claim 7, further comprising: a torque converter including alock-up clutch passage; the body produces lock-up clutch pressure; and asupport that includes a path that communicates lock-up clutch pressureto the lock-up clutch passage.
 12. The system of claim 7, furthercomprising: a torque converter including a converter release passage;wherein the body produces converter release pressure; and a support thatincludes a path that communicates converter release pressure to theconverter release passage.
 13. A system for supplying fluid totransmission elements, comprising: a shaft including passages; a lubesource; a support including fluid paths communicating clutch-applypressures and the lube source to a respective passage; a clutch hubcontaining clutches, each clutch including a servo and a balance volumespaced axially from the support, the clutch hub communicatingclutch-apply pressure from each of the passages to a respective servo,and communicating the lube source to the balance volumes; a torqueconverter including a lock-up clutch passage; and wherein a control bodyproduces lock-up clutch pressure, and the support paths include a paththat communicates lock-up clutch pressure to the lock-up clutch passage.14. The system of claim 13, wherein: the control body produces aclutch-apply pressure for each of three of the clutches; the shaftpassages include four passages, each of first, second and third passagescommunicating clutch-apply pressure to one of the clutch servos, and afourth passage communicating the lube source to the balance volumes. 15.The system of claim 13, further comprising: the control body producingbrake-apply pressures; brakes, each brake including a brake servo; andwherein the support includes second paths that communicate each of thebrake-apply pressures to a respective brake servo.
 16. The system ofclaim 13 further comprising: the control body producing a brake-applypressure; a brake including a brake servo; and wherein the supportincludes a path that communicates the brake-apply pressure to the brakeservo.
 17. The system of claim 13, further comprising: the torqueconverter including a converter charge passage; and wherein the controlbody produces converter charge pressure, and the support paths include apath that communicates converter charge pressure to the converter chargepassage.
 18. A system for supplying fluid to transmission controlelements, comprising: a body producing clutch-apply pressures and a lubesource; clutches, each clutch including a servo and a balance volume; ashaft including passages; a support including paths communicating eachof the clutch-apply pressures and the lube source to a respectivepassage; a clutch hub communicating clutch-apply pressure from each ofthe passages to a respective servo, and communicating the lube source tothe balance volumes; a torque converter including a converter releasepassage; and wherein the body produces converter release pressure, andthe support paths include a path that communicates converter releasepressure to the converter release passage.